PEM fuel cell as a membrane reactor

The H-2-O-2 proton-exchange membrane (PEM) fuel cell, among numerous other potential applications now slated to provide the motive power for the next generation of highly efficient and largely pollution-free automobiles, is a n incomparable membrane reactor, comprising an exquisitely designed membran e-electrode-assembly (MEA), a five-layer composite of two gas-diffusion lay ers, two supported-catalyst layers, and a PEM. The device allows catalytic reaction and separation of hydrogen and oxygen as well as protons and elect rons. This paper describes the structure and performance of the PEM fuel ce ll considered as a membrane reactor and develops an analytical transport-re action model that, despite some assumptions, captures the essential feature s of the device very well. The key assumptions are that transport resistanc e as well as ohmic drop are negligible in the catalyst layer. While the lat ter is defensible, the former causes deviations at high current densities. Nonetheless, the model predicts the fuel cell performance well with paramet er values reported in the literature. (C) 2001 Published by Elsevier Scienc e B.V.